Unable to connect to domain host mail server

[#1]

Firstly, I'm posting this in the general Broadband section as I don't believe that it is related to Plusnet's e-mail service.

I have a domain hosted by another web host and started having problems sending and receiving mail yesterday. I am using Airmail on a Mac and Mail on my iPhone and iPad. My mail server settings are correct but during testing, I have alternated between SSL and non-SSL ports. By accident, I discovered that when my iPhone was connected via 3G (there is no 4G service), it managed to connect to the mail server without issue. I then connected my Mac to the iPhone hotspot and again, there were no problems.

I tried rebooting my router - which gave me a new IP address and Airmail on my Mac connected to the mail server without any problems. However, 10 or 15 minutes later, there was a problem, again. This time, I just disconnected the broadband and reconnected and the mail server connection was established again.

I don't have any firewalls running on my Mac and for the purpose of testing, I disabled the Plusnet Hub One firewall.

As I can alway connect using my iPhone's mobile data but seems to get 'blocked' (merely for want of a better word) after a while when trying to connect via broadband, I'm guessing that the broadband connection is where the problem lies.

If anybody has any thoughts' I'd be grateful.

[#2]

Moderators Note

This topic has been moved from ADSL Broadband to Technical Help

[#3]

This sounds like a question for your domain hosting service - "Why might they be refusing connections on some IP addresses?".

[#4]

Disabling the firewall on the hub is not a good idea, that stops unsolicited inbound connection.
You are trying to make an outbound connection.
No error messages returned by airmail?
As @Townman says it seems the issue is with your host rejecting the connection - especially if your connection remains active and all other services are working.

[#5]

As I said, I disabled the firewall for the purpose of testing.

Airmail said that my settings are incorrect - which is incorrect as I am occasionally able to log in - so I took it to be a generic error.

I understand your line of thought but as I am unable to use any POP or SMTP services, it is also possible that those ports could be 'experiencing problems' and not affect any other traffic.

I have already been in contact with the web host and they don't seem to think, or want to concede, that the problem is with them.

[#6]

Thanks for getting in touch @flamesong and I'm sorry to hear that you're having issues here. As @Townman has mentioned, it's not really Plusnet who are answerable to this query, as we don't block access to emails / domains on our residential broadband. 

Our email service does have a spam filter which occasionally gets things wrong, but with you using your domain's mail server, this won't be the issue. 

I'd have perhaps gone down the router of maybe even assigning a static IP to your connection, but with this issue occurring on both static IP's that have recently been assigned, this doesn't appear to be the problem either.